Segments
A segment is who a group-scoped event is about. A static segment keeps a list you add to; a dynamic segment holds whoever's attributes contain its filter, so nobody keeps it up. Beside the segments somebody keeps are temporary lists, picked by a person for one send: you can see them, but a key cannot change one and an event cannot name one. In the Subscription business pack a segment is, for example, “Annual plans”.
PATCHUpdate a segment
Requires groups:write. Send only what changes — except attributes, which is replaced whole. kind and member_kind never change: make a new segment instead. A body that changes nothing is refused.
200 with the updated segment. 409 on a temporary list, which a key cannot change.
One segment: the same fields in every pack. Press Response on the sample to see one whole.
On failure the body is { error, code } instead.